Identification and characterization of a novel sesquiterpene synthase, 4-amorphen-11-ol synthase, from <i>Artemisia maritima</i>

Abstract

Artemisinin, a sesquiterpene lactone exhibiting effective antimalarial activity, is produced by only Artemisia annua plant. A key step in artemisinin biosynthesis is the cyclization of farnesyl pyrophosphate (FPP) to amorpha-4,11diene catalyzed by amorpha-4,11-diene synthase (AaADS). Intriguingly, several non-artemisinin-producing Artemisia plants also express genes highly homologous to AaADS. Our previous functional analysis of these homologous enzymes revealed that they catalyzed the synthesis of rare natural sesquiterpenoids. In this study, we analyzed the function of another putative sesquiterpene synthase highly homologous to AaADS from A. maritima. Unlike AaADS, in vivo enzymatic assay showed that this enzyme cyclized FPP to 4-amorphen-11-ol, a precursor of several gastroprotective agents. The discovery of 4-amorphen-11-ol synthase (AmAOS) and the successful de novo production of 4-amorphen-11-ol in engineered yeast demonstrated herein provides insights into the methods used to enhance its production for future application.

Amorpha-4,11-diene synthase: a key enzyme in artemisinin biosynthesis and engineering

“…Similarly, orthologs of CYP71AV1 (94% amino acid identity) from the Artemisia genus (e.g., A. afra and A. absinthium ) converted amorpha-4,11-diene to artemisinic alcohol (Komori et al 2013 ). However, ADS homologs from other Artemisia species (e.g., A. absinthium, A. kurramensis, and A. maritima ) did not produce amorpha-4,11-diene (Muangphrom et al 2016 ); a homologous synthase from A. maritima produced amorphen-4,11-ol (Muangphrom et al 2018 ). Although further investigation is required, accumulated data is in favor of the hypothesis that artemisinin production in A. annua is attributed to the emergence of ADS .…”

Identification and characterization of novel sesquiterpene synthases TPS9 and TPS12 fromAquilaria sinensis

“…Among them, cis -sesquisabinene has not been previously detected in A. sinensis . Although cedrol has been found in the essential oil from A. sinensis and A. crassna ( Gao et al, 2019 ; Thanh et al, 2015 ), and can be formed by sesquiterpene synthases isolated from other plant species, such as Artemisia apiacea ( Kanagarajan et al, 2012 ) and Artemisia maritima ( Muangphrom et al, 2018 ) yet, there are no previous reports of a sesquiterpene synthase in A. sinensis that can catalyze cedrol.…”